Such a method is used for manufacturing parts in thermostructural composite materials, e.g. materials capable of constituting structural elements and of retaining their mechanical properties at high temperatures.
Examples of thermostructural composite materials are the carbon-carbon (C-C) type composites and the ceramic matrix composites (CMC).
In a C-C type composite, the reinforcement texture is in carbon fibers and is densified by carbon, while in a CMC-type composite, the reinforcement texture is in refractory fibers (carbon or ceramic fibers) and is densified by a ceramic matrix.
When the thermostructural composite material parts are produced by chemical vapor infiltration of the material constituting the matrix, through the accessible porosity of the reinforcement texture, the shape of said texture is generally maintained by means of a tool, normally in graphite.
A problem which has been arising for a long time is that of releasing the densified part from the tool, because of the adherence to said tool. Said adherence is due to the material constituting the matrix which is deposited through the porosity of the reinforcement texture and also on the surface of the tool.
A number of solutions have been proposed for reducing the adherence to the tool, notably by treating the surface of the latter.
However, the conventional solutions have proved to have limited efficiency, particularly in the case of three-dimensional (3D) type fibrous reinforcement textures. Compared with the two-dimensional (2D) type textures in which the fibers extend in parallel to the faces of the texture, the 3 D textures contain fibers which extend in directions forming a non-zero angle with respect to the faces of the texture. Said fibers, which issue onto each face of the texture, offer multiple points of contact with the tool, thus helping adherence. The adherence is all the stronger as the surface of the texture is bulging with fibers.